Unison is a file-synchronization tool for POSIX-compliant systems (e.g. *BSD, GNU/Linux, macOS) and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other.
Publisher’s description
What is Unison?
Unison is an open-source system utilitie program for Windows from Benjamin Pierce. It is written in OCaml. Besides Windows, it is available for Linux.
Installation and requirements
Official installers exist for 64-bit and 32-bit as Portable. It runs without installation (portable).
Updates and version history
The current version is 2.54.0, released on May 1, 2026. 3 versions are listed since January 10, 2025, each with links to its own installer files. That is about 2.3 releases a year.
Popularity and file types
The source code on GitHub (bcpierce00/unison) has 5,542 stars. Similar programs include AutoHotkey, Bazel and Simplenote.
Project description on GitHub: “Unison file synchronizer”
Pros / Cons
Pros
- Open source: the code can be inspected and built by anyone
- Portable: runs without installation
- Also runs on Linux
- Large user base
Cons
- No native ARM64 build
In short: Unison is an open-source system utilitie tool for 64-bit and 32-bit PCs.
Is Unison safe to download?
- The file is served by github.com, the publisher’s own domain
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
8E0C9070824DC7E3F207D54C8AFDEC1AF55AC26AF2740D0D5D7B6E00C44D5FAB· Open the VirusTotal report for this hash - The link has not been checked yet
- The source code is public
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Security practices (OpenSSF Scorecard)
Automated checks of the bcpierce00/unison repository on GitHub by the Open Source Security Foundation, last run on October 19, 2026.
- Actively maintained10
- No binaries in the repository10
- No dangerous workflows10
- Licence declared10
- Code review9
- Restricted token permissions0
- Pinned dependencies0
- OpenSSF Best Practices badge0
- Security policy0
- Fuzzing0
- Signed releases0
- Static code analysis0
The score rates how the project is developed and released, not whether the program is safe to install. scorecard.dev
Recent versions
All 3 versions ›3 versions over 1 year · about 2.3 a year
| Version | Date | Size | Files |
|---|---|---|---|
| 2.54.0Latest | May 1, 2026 | — | 32-bit ZIP64-bit ZIP |
| 2.53.8 | November 5, 2025 | — | 64-bit ZIP |
| 2.53.7 | January 10, 2025 | — | 64-bit ZIP |
Install from the command line
Silent install ›winget install --id bcpierce00.unison -eRelated guide: How to use winget: install and update apps
Also for other systems
flatpak install flathub io.github.bcpierce00.unisonInformation
- Publisher
- Benjamin Pierce
- Category
- System utilities
- Licence
- GPL-3.0
- Price
- Free
- Source code
- github.com/bcpierce00/unison
- Written in
- OCaml
- Content rating
- All ages
- Requires
- Windows 11 / 10
- Architecture
- 64-bit, 32-bit
- Installer
- Portable
- Other platforms
- Linux
- Version
- 2.54.0
- Released
- May 1, 2026
- Added to the catalogue
- January 10, 2025
- Versions listed
- 3
- Updates / year
- 2.3
- GitHub stars
- 5,542
- GitHub forks
- 277
- Website
- github.com
- winget ID
- bcpierce00.unison
Ratings and reviews
No reviews yet. Be the first to rate it.
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Frequently asked questions
Is Unison free?
Yes. Unison is open-source software under the GPL-3.0 licence.
Is Unison safe to download?
The download comes from github.com, which belongs to the publisher; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install Unison with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Does Unison run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 64-bit and 32-bit version through emulation.
Where can I download an older version of Unison?
The versions page lists all 3 versions with links to their official installer files, back to January 10, 2025.
Can I use Unison without administrator rights?
Yes, it is portable: unpack and run it.
What are alternatives to Unison?
AutoHotkey, Bazel, Simplenote, osquery and Hydrus Network. The alternatives page compares them.
